Variables - discreet and continuous random variables

I'm having problems with this one -

Which of these variables are discreet and which are continuous random variables?
a. The number of new accounts established by a salesperson in a year.
b. The time between customer arrivals to a bank ATM.
c. The number of customers in Big Nick's barber shop.
d. The amount of fuel in your car's gas tank.
e. The number of minorities on a jury.
f. The outside temperature today.

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a. The number of new accounts established by a salesperson in a year - discrete
b. The ...